Insulation of MDPE pipe under suspended floor?

[gdickin2]

Going to replace the lead supply pipe in my property as far as I can go without digging up the garden.
Current lead pipe runs to front of property (Victorian era) and then down under suspended floor (I will probably join MDPE to the lead pipe at some point under the floor) along the length of the house to the kitchen area.
Once the pipe enters the kitchen area (which is not a suspended floor - it is concrete on sand - why this was never suspended I don't know) it is buried approx. 80cm under the floor, but runs close (<20 cm) to the external wall.
Can you tell me if the MDPE pipe needs to be insulated along it's length where it runs under the suspended floor part?
Once into the kitchen area, I was hoping to run the MDPE through aa conduit (32mm waste) and bury under a new concrete floor - are there any depth and insulation requirements for this section of the pipe?

Many thanks.

 

[muggles]

If it's in a suspended floor it's technically outside (it will get as cold as outside in the winter) so it should be lagged, preferably with thick exterior-grade lagging. If it's buried in the concrete to a depth of 750-1350mm then no lagging will be required, any less than 750mm and it should be lagged

 

[gdickin2]

Thanks for that. Is there any specific kind/manufacture of lagging I should be using or is the rubber insulation from the diy store sufficient?